I'll believe it when I see it. These days, words are basically meaningless from these large tech companies. Actions are what matter.
at the very least, I'm not convinced this internal branch and AOSP will be close to feature parity if they do throw some stuff out.
GrapheneOS actually explicitly pushes for services to switch away from Play Integrity API or SafetyNet API towards the Android Attestation API for that reason.
https://grapheneos.org/articles/attestation-compatibility-gu...
And notably, long term if Google becomes an unreliable maintainer for Android, the other major Android providers are likely to coordinate a list of "approved signing keys" so that apps can use those with the standard Android HW Attestation API.